Products made from absorbent fibrous webs are used for a variety of purposes. For example, rolled absorbent products such as paper towels and toilet tissues are in constant use in modern industrialized societies. Such rolled products, as well as related products including facial tissues, napkins, and the like, are typically packaged for retail sale in flexible polymer packaging. Packaging can include single rolls in a polymeric film wrapper or packages of multiple rolled products bundled into a single larger polymeric film wrapper.
Current approaches to forming packages of rolled products include well known “flow wrap” technologies. Flow wrappers have an infeed mechanism, such as a conveyor or pushing device, a film feed assembly, a forming area, a cutting head, and a discharge area. Product to be wrapped is placed on the infeed conveyor, which moves generally horizontally to deliver product to a forming area. A single film can be drawn from a film feed assembly into the forming area, where the film is formed over a forming horn into a tube around the product as the product is pushed into the tube. The tube can be sealed along its edges to form a partially sealed package, the partially sealed package still being open at two its two ends after the film is cut at the trailing end. For certain packages, including packages of rolled products, after forming the partially sealed packages the partially sealed packages are directed at a 90-degree angle into an end sealer apparatus, which closes and seals the open ends of each tube, thereby creating a completely closed package.
In current systems that use conveying systems to move products and packages, the 90-degree re-direction is achieved by a mechanism that transfers product to a discharge mechanism that is perpendicular to the infeed, such that the two open ends of the partially sealed package which were oriented in line with the direction of the conveyor, are oriented orthogonally to the direction of travel, i.e., toward the two sides of the conveyor. The two open ends are then folded and sealed to form a finished package. Such conveyors necessitate an L-shape configuration, as described in co-owned and co-pending application Ser. No. 12/680,276, filed Nov. 19, 2012 in the name of Overley et al.
While L-shaped conveyors for flow wrapping packaging are very common and useful for packaging rolled products, the requirement that the conveying path be L-shaped presents at least two problems. First, the L-shape disrupts a linear path, increasing the “footprint” or floor space necessary for the conveying equipment. Often the packaged rolled products that are diverted from a first direction to a second direction at a right angle, need to be reintroduced into a conveying path in the first direction with additional right-angle turns. Secondly, the L-shaped deviation from a linear conveying path can work against a manufacturer's desire for modularity in a line of modular unit operations related to conveying, arranging, packaging, and bundling of rolled products.
Certain packages of rolled products, particularly packages of multiple rolls, that can lie flat with a relatively large package area resting on the conveyor belt can be turned by way the use of a conveying system having two side-by-side conveyer belts that can be driven at different speeds. By driving one of the belts faster than the other, the product that spans both belts will be caused to rotate in the plane of the moving belts. By controlling the relative speeds of the belts, the a partially wrapped package of rolled product can be made to rotate a predetermined rotation, such as 90 degrees, through a conveying distance, and thereafter conveyed in a straight path into a folder/sealer operation for final folding and sealing.
The problem with two side-by-side conveyer belts that can be driven at different speeds is with respect to small or dimensionally narrow products, such as single rolls of rolled product. Specifically, a rolled product having dimensions typically associated with paper towels or toilet paper, when oriented such that the length dimension is parallel with the direction of conveyance, will sit in the gap between the two side-by-side belts, and will resist rotation. Furthermore, rotation is not as controlled, as the partially rotated rolled product tends itself to roll (i.e. spin about its axis) on the conveyor belt, thereby changing position during conveyance.
Accordingly, there is an unmet need for a conveying system for flow wrapping rolled products that eliminates the need for an L-shaped conveying path.
Further, there is an unmet need for a conveying system that can reliably handle both individual rolled products and packaged products of multiple rolled products.